Silverman et al. teach in U.S. Pat. No. 4,213,038 an access control system with an identification card. The card has machine recordable indicia used to choose a master microspot pattern from the machine's memory. This master pattern is compared with an identical pattern on the card for verification. The card also has space for a picture and a signature. Similarly, Idelson et al. (U.S. Pat. No. 4,151,667) teach an identification card having a photograph and a phosphorescent bar code pattern used for verification. The amount of information these cards can hold is extremely limited. Random microspot patterns can only be used for verification, while bar codes can only represent a small amount of specific data.
In U.S. Pat. No. 4,254,329 to Gokey et al., an information retrieval system includes a microfiche data base of two types of microfiche cards. One type is machine readable only, while the other has both machine readable and visually readable information. This information cannot be updated.
In U.S. Pat. No. 4,236,332, Domo discloses a medical record card containing a microfilm portion having some data visible to the eye and other data visible by magnification. The directly visible data is alphanumeric character codes pertaining to emergency medical conditions of the patient and the magnifiable data portions detail the medical history. This information cannot be updated.
In optical data storage cards, reliability and ease of reading the data are important. Data may be recorded in an office environment, but need to be read in a dirty environment or when no card reading machine is available, such as in an emergency. For example, medical-record cards should be readable in an ambulance, at the scene of an accident, or on a battlefield. In such conditions, it may be difficult or impossible to read the digitally recorded data.
An object of the invention is to provide laser written data, ordinarily only machine readable, which can be read without a machine.
Another object of the invention is to provide updatable information on a laser recordable card in both machine readable digital form and human readable without a machine.